Overhead door construction



Feb. l5,l 1955 R, WOLF 2,702,082

OVERHEAD DooR coNs'rRucfrIoN Filed Feb. 4, 195o z sheets-sheet 1 IN V EN TOR.

Feb. 15, 1955 C, R, WOLF OVERHEAD DOOR CONSTRUCTION 2 Sheets-Sheet 2 Filed Feb. 4, 1950 INVENToR. B'eclz'' Z United States Patent O OVERHEAD DOOR CONSTRUCTION Cecil R. Wolf, Rock Falls, Ill., assignor to Frantz Manufacturing Co., Sterling, lll., a corporation of Illinois Application February 4, 1950, Serial No. 142,401

s claims. (Cl. 16o-201) This invention is concerned generally with overhead garage doors and particularly wltn structure tor preventing Oversnooting and rebounding ot such doors. p

rleretot'ore, garage doors ot' the overhead opening type have been beset with a common problem. As the doors reach overhead open position tney are traveling at a considerabie rate of speed and continue to move past their tully opened position and then rebound to a partially closed position. The door may oscillate several times about its t'ully Opened position and all of the oscillations including, particularly, the original overshoot a small part of the weight ot' the door must be counterbalanced. A stronger spring must be used to retard closing ot' the door and to aid in overcoming the inertia of the door when the door is iirst started upward toward opened position than is necessary to counterbalance the upwardly moving door to the same extent. Consequently, the spring action and the upward lift by the person operating the door imparts a considerable momentumto the door. This momentum along with the residual spring tension when the door is in overhead opened position are the forces causing the door to overshoot. When the door has overshot some distance, it encounters a stop which should be resilient to prevent damage to the door and 'associated mechanism and a resilient stop causes the door to rebound.

lt is an important object of this invention to provide means for braking an overhead garage door when in nearly fully opened overhead position.

It is an ancillary object of this invention to provide overhead garage door braking structure which is adjustable to vary the braking elect.

' Other and further objects and advantages of the present invention will be apparent from the following description when taken in conjunction with the accompanying drawings in which:

Fig. 1 is a fragmentary longitudinal sectional view showing a garage door and associated mounting structure in a garage;

Fig. 2 shows one end of a spring and spring mounting structure in one position;

Fig. 3 is a view similar to Fig. 2 showing the spring and mounting structure in different relative positions;

Fig. 4 is a perspective view of the spring anchor member;

Fig. 5 is a fragmentary view showing part of the spring mounting and tension altering structure;

Fig. 6 is a fragmentary perspective view showing the door braking mechanism;

Fig. 7 is an end view of the track mounting structure showing the brake adjusting track; and

Fig. 8 is a fragmentary top view showing the door braking structure.

Generally, my door braking structure includes a brake plate mounted on each ofv the two door carrying tracks adjacent the'ends of the tracks where the brake plate 2,102,082 Patented Feb. 15, 1955 .will frictionally engage the upper edges of the door as the door approaches fully opened position. Structure is provided for varying the spacing between the two brake plates so that doors which vary somewhat in width can be accommodated and so that more or less braking force can bev applied by causing the brake plates to bear against the edges of the door with greater or less force as is required.

A pair of counterbalancing springs is used with one end of each spring secured by means of a member threaded into' the endnof the spring. The distance that the member is threaded into the spring determines the effective length of the spring and hence the spring rate per inch of the spring or amount of weight required to stretch the spring per inch. By threading the member different distances into the spring the tension in door closed position may be altered while the tension in door opened position may be maintained substantially constant by a conventional connection at the other end of the spring to vary the degree which the spring is stretched in door opened position without altering the effective length of the spring. o

A garage door construction is shown generally in Fig.v 1 and comprises a door jamb 10 and a hinged sectional overhead opening door 12 of the usual type. The door is mounted by means of rollers 13 fitting in a substantially`channel shaped track 14 having substantially vertical and substantially horizontal sections 16 and 18, respectively, connected by a curved section 20. As will be noted, the lower portion of the substantially vertical section of the track is mounted closer to the door jamb 10 than is the upper portion and the rollers 13 are spaced at correspondingly varying distances from the door 12 with the lower rollers being closest and the upperrollers being farthest from the door in order that the door may be wedged against the jamb as it is closed. The tracks 18 are supported at their rear extremities by means of a cross angle 22 and a plurality of straps or hangers 24 secured to any suitable cross member 26 such as a rafter of the garage. The tracks 14 are supported adjacent the curved sections 20 by means of a bracket 28 bolted or otherwise secured to the tracks and suitably secured to the -door jamb or garage frame. The lower substantially vertical portions of the tracks are supported from the door jamb or garage frame in any desirable manner.

A counterbalancing helical spring 30 is secured on each side of the door and each spring is secured at its rear end by means of an anchor member 32 (Figs. 2, 3 and 4). Each anchor member 32 is secured to the horizontal ange of the cross angle l22 by means such as a bolt and nut 34. I Each anchor member 32 comprises a substantially flat bar apertured on one end for mounting on the cross angle 22 and provided at its opposite end with a section having scalloped or toothed edges. The scallops comprise half round grooves arranged substantially as a section of a helix so that the anchor member 32 may be threaded into the helical counterbalancing spring` 30. Each tooth is blunt at its outer edge in order toy spread the coils of the helical spring slightly and this along with the constriction of the coils upon stretching the spring insure that the spring will tightly grip the anchor member.

The opposite end of each spring 30 has `a sheave or pulley 38 secured to it in any suitable manner. A cable y 40 passes over each pulley or sheave 38 and over a second pulley or sheave 42 and extends to the lower edgeA of the door 12. Each cable 40 is suitably secured to a chain 44 having one link looped over a hook 46 mounted in the door jamb 10.

To adjust each spring 30 to compensate for differences in door weight andin spring strength, the anchor member 32 is threaded into the spring 30 a greater or lesserdis-v A inactive, and the etective length of the spring has been t 2,702,0sa

distance and hence a heavier door may be counterbal-V anced. Besides shortening vthe effective length of the spring as ,a `consequence of threading the anchor member 32 farther into the spring, the spring is stretched a slightly greater distance when the door is in overhead position. To compensate for this, the chain 44 is .moved from the hook 46 and a link more remotely disposed from the left end of the spring 30 is looped over the hook 46. By adjusting both the distance the anchor member is threaded into the spring and by changing .the link of the chain looped over the hook 46, the tension of the spring may be increased when the door is in closed position without materially altering the tension. of the spring when the door is in overhead opened position.

The brake structure is shown in detail in Figs. 6-8i A brake plate 48 is secured to each horizontal section on track 18 adjacent the rear end thereof to engage each lateral edge of the door near the top of the door. Each brake plate comprises a depending portion 50 riveted, bolted or otherwise suitably secured to the outer face of the track 18. An offset portion 52 supports a friction plate section 54 having frictional braking surfacesand provided with bevelled or bent ends, 56. The friction plate section 54 may be faced with friction material if desired, although it has been found that a plain steel plate is satisfactory. A wear strip 58 is applied to each upper corner of the door particularly along each lateral edge t provide braking surfaces to engage the friction plate sections 54. As the door approaches fully opened position as shown in Figs. 6-8 the wear strip S8 encounters the friction sections 54 of each brake plate 48 and the door is frictionally brought to a st'op. The bevelled ends 56 of the friction section act to center the door between the friction sections 54 and if the friction sections 54 are slightly twisted or canted as shown in Fig. 8, the door is wedged between the brakes. creases with the distance the door moves between the brakes so that the spreading force is increased the farther the door moves.

It is not necessary to twist the friction sections 54 as shown in Fig. 8 as the braking force due to friction also increases with increasing surface area of contact. The friction sections may have their top edges tipped toward each other slightly to increase the braking action. The brakeplates will not bend, but the tracks are sufficiently resilient to twist slightly so -that the brake friction surfaces may engage the wear strips evenly. By stopping 4 substantially J-shaped bolt 80 is fitted. The hook or bight portion of the bolt engages an aperture 82in the horizontal flange of the cross angle 22 and a nut 84 threaded on the other end of the boltpulls the bracket 68 and associated bracket 14 toward the aperture 82. If both tracks were mountedsimilarly to the right one by a bolt placed through a circularaperture in the horizontal flange of'the cross angle 22, it would be impossible to The wedging action inthe door with increasing brake action a smooth stop"` is insured without shocks.

As set forth previously in rather general terms, the

rear ends of the tracks 18 are supported from a cross angle 22. The vertical flange of the cross angle acts as a positive stop to limit the rearward movement of the door and is provided with a plurality of apertures ad jacent each'end so that supporting straps 24 may be at, tached at any convenient location. The straps 24 are perforated'to receive bolts 62 in any of a plurality of positions so that the'height of the cross angle 22 may be determined readily. One of the tracks 14, which is the right one, as shown in Fig. 7 is secured to the horizontal ange of the cross angle 22` by means of an L- shaped bracket 64 riveted or otherwise secured to the vertical face of lthe track. The bolt 66 passes through the upper face of the track, through the bracket 64 and through an aperture in the horizontal flange of the cross angle 22 and is secured in position by a nut threaded thereon.l justably secured in position by means of a substantially U-shaped bracket 68 having horizontal and vertical anges 70 and 72 lying in contact with the horizontal and vertical faces of the track section 18. The bracket may be secured to the track by means of a rivet or other suitable securing means while a bolt 74 passes through the track and the horizontal bracket ange 70 and through an elongated aperture in the horizontal flange of the cross angle 22. The bolt 74 is held in place by a nut 76 threaded on the upper. end thereof. Due to the elongated aperture in the horizontal ange of the cross angle 22 the -track 14 can be adjusted transversely to cause the brakes The other horizontal track section 18 is adadjust the spacing between the tracks to adjust the braking action. If an elongated slot were used alone in the horizontal flange of the cross angle 22 the tracks would gradually spread and the braking action would fail. The J-shaped bolt prevents such spreading and allows the left track to be pulled in so that any desired force can be exerted by the brakes on the door.

In the usual overhead door construction,.the free or inner end of each trackis rigidly supported so that the tracks cannot move relative to the garage or to each other. Due to the cross angle 22 the tracks as herein disclosed are not free to move relative to one another, but the mounting of the cross angle by the single straps 24 is sufficiently exible to allow the tracks to shift as a' unit. If the door is somewhat olf center due to warping of the door or other factors it will strike one of the brakes 48 ahead of the other. The beveled edges 56 will supply a centralizing force between the tracks and the door, and the tracks, having less inertia than the door, will shift to a central position about the door to prevent any darnage to the door or tracks.

It is apparent that an overhead door construction has been resented which eliminates overshooting and rebounding of the door. Simple and effective structure for braking the door when in nearly opened position has been disclosed and structure has been disclosed by means of which the braking action may be varied as desired.

Although a specific example has been shown and described it is apparent that this is for illustrative purposes only, and that my invention comprehends all that which may fall fairly within the spirit and scope of the appended claims. l

I claim:

1. In a shiftable door construction, a door shiftable between closed and open positions, a plurality of substantially parallel tracks for guiding said door between said positions, and a pair of rigid members rigidly fixed on said tracks and providing frictional surfaces at opposite sides of said door when in one of said positions frictionally toengage opposite vsurfaces of said door to arrest said door in said position.

2.* A door construction as set forth in claim 1 in which the rigid members providing the frictional surfacesare canted relative to adjacent edge surfaces of said door whereby to wedge said door between said pair of rigid 'surfaces and to centralize said door.

3. In a shiftable door construction, a door shiftable between closed and opened positions, a plurality of tracks for guiding said door between said positions, means providing a pair of surfaces mounted on opposite sides of said door and adjacent the rear inner ends of said tracks to frictionally engage opposite surfaces of said door to brake said door in that position, and means for adjusting the spacing between said surfaces to adjust the braking action exerted thereby.

4. In an overhead door construction, a door shiftable Y tween said positions, means for supporting said tracks,

a plate on each track frictionally engaging opposite edges of said door in one of said positions and means for adjusting the spacing between said tracks to vary the braking effect of said plates, said last named means including a bar supporting vone of said tracks and having spaced apertures therein at least one of which is elongated, a connection from said track extending through said elongated aperture to support said track, a substantially J-shaped bolt extending substantially from said track through another of said apertures, and a nut on the,

for adjusting the position of at least'one of said tracks f on said rigid member to vary the spacing between said tracks and thus to vary the braking effect of said brake plates on said door.

7. In an overhead door construction, a door shiftable between closed and opened overhead positions, a pair of tracks for guiding said door from closed to opened overhead position, rigid means interconnecting the rear ends of said tracks, means for flexibly supporting the rear ends of said tracks, and cooperating camming means carried by said door and by said tracks near the rear ends thereof to apply a contralizing force between said tracks and said door as said door approaches opened overhead position to centralize the door and the tracks relative to one another, the flexibly supported rear ends of the tracks shifting transversely to effect such centralizing.

8. In'an overhead door construction, a door shiftable between closed and opened overhead positions, a plurality of substantially flexible tracks for guiding said door between said positions, a pair of rigid brake plates rigidly connected to the tracks, one brake plate being on each track, surfaces on opposite edges of said door being adapted to engage said brake plates when said door approaches one of said positions, and rigid means connecting the rear ends of said tracks to maintain substans tially constant spacing between said tracks while allow-- ing the tracks to ex as the rigid brake plates engage the opposite edges of saiddoor.

References Cited in the ile of this patent -UNrrED .STATES 4PATENTS 260,920 Allen -c July 11, 1882 367,020 Barlow July 26. 1887 695,836 Rhodes Mar.` 18, 1902 897,747 .Joyce Sept.1, 1908 1,603,379 Dautrick Oct. 19, `1926 1,698,118 Barrows Ian. 8, 1929 1,931,651 Ferris Oct. 24, 1933 2,139,383 Robinson Dec. 6, 1938 2,142,562 Greegor et a1 Jam 3, 19,39 2,166,746 Bartel July 18, 1939 2,538,626 Olsen Jan. 16. 1951 2,584,134 Knutson Feb. 5, 1952 v FOREIGN PATENTS 297,997 Great Britain Oct. 4, 1928 

